Techniques for communicating beam information

ABSTRACT

The disclosed technology includes techniques for facilitating the operation of a multi-antenna communication system. The disclosed technology can be implemented to provide a method for wireless communications which includes receiving, by a user device, an indication about an association between multiple reference resources and a target resource at the user device. The association includes properties of a communication channel to and/or from the user device, and wherein at least one property of the communication channel is different among the multiple reference resources, and performing wireless communication using the indication.

CROSS REFERENCE TO RELATED APPLICATIONS

This patent document is a continuation of and claims benefit of priorityof International Patent Application No. PCT/CN2017/083348, filed on May5, 2017. The entire content of the before-mentioned patent applicationis incorporated by reference as part of the disclosure of thisapplication.

TECHNICAL FIELD

This document relates to systems, devices and techniques for wirelesscommunications.

BACKGROUND

Efforts are currently underway to define next generation communicationnetworks that provide greater deployment flexibility, support for amultitude of devices and services and different technologies forefficient bandwidth utilization.

SUMMARY

This document describes technologies, among other things, techniques forfacilitating the operation of a multi-antenna communication system.

In one aspect, the disclosed technology can be implemented to provide amethod for wireless communications which includes receiving, by a userdevice, an indication about an association between X referenceresources, where X is an integer greater than 1, and a target resourceat the user device, wherein the association includes properties of acommunication channel to and/or from the user device, and wherein atleast one property of the communication channel is different among themultiple reference resources. In some implementations, the methodfurther includes performing wireless communication using the indication.

In another aspect, the disclosed technology can be implemented toprovide a method of wireless communications that includes transmitting,to a user device, an indication about an association between X referenceresources, where X is an integer greater than 1, and a target resourceat the user device, wherein the association includes properties of acommunication channel to and/or from the user device, and wherein atleast one property of the communication channel is different among themultiple reference resources. In some implementations, this methodfurther includes performing a transmission that uses at least some ofthe multiple reference resources to transmit a signal to the userdevice.

The details of one or more implementations are set forth in theaccompanying attachments, the drawings, and the description below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an example of a wireless communications network.

FIG. 2 shows an example of a wireless communications apparatus.

FIG. 3 shows an example of transmission between a base station and auser device.

FIG. 4 is a flowchart for an example wireless communication method.

FIG. 5 is a flowchart for an example wireless communication method.

FIG. 6 is a flowchart for an example wireless communication method.

FIG. 7 is a flowchart for an example wireless communication method.

Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

The Third generation partnership project (3GPP) has started thestandardization process of new radio access technology for the 5thGeneration wireless system. The new technology will consider frequencyranges up to 100 GHz. High-frequency communication, e.g., above 6 GHz,suffers from significant path loss and penetration loss compared tolower frequency communication, e.g., in the 3 GHz and 5 GHz bands. Onesolution to solve this problem is to deploy a large antenna array, e.g.,an antenna array with many antennas, to achieve high beamforming gain tocompensate the loss. Using a large antenna array can be a practicalsolution in a high frequency system due to the shortened wavelength of ahigh-frequency signal relative to a signal at a lower frequency. Foraround 30/70 GHz, up to 1024Tx antennas may be used. When the number ofantennas used is so large, fully exploiting the MIMO gain by anall-digital beamforming in the baseband is not realistic due to problemson hardware cost, power consumption and standardization complexity.

The techniques described in the present document can be used toimplement wireless devices that overcome the above-described, and other,problems. For example, using the disclosed techniques, a multi-antennascheme that uses an analog/hybrid (e.g., analog and digital) beamformingfor New Radio (NR) interface could be implemented in devices thatperform transmission and reception at high frequencies.

FIG. 1 shows an example wireless communications network 100. The network100 includes a base station BS 102 and multiple user devices 106 beingable to communicate with each other over a transmission medium 104. Thetransmissions from the BS 102 to the devices 106 are generally calleddownlink or downstream transmissions. The transmissions from the devices106 to the BS 102 are generally called uplink or upstream transmissions.The transmission medium 104 typically is wireless (air) medium. The BS102 may also be communicatively coupled with other base stations orother equipment in the network via a backhaul or an access networkconnection 112.

FIG. 2 is a block diagram of an example of a wireless communicationapparatus 200. The apparatus 200 includes a processor 210 that may beconfigured to implement one of the techniques described herein,transceiver electronics 215 that is able to transmit signals or receivesignals using the antenna(s) 220, and one or more memories 205 that maybe used to store instructions executable by the processor 210 and/ordata storage. As discussed throughout the document, the number ofantennas 220 could be large (e.g., 8, 16, 32, or 64 or more) and such anapparatus may benefit from techniques described herein.

Reference signals are commonly used in wireless communications for avariety of reasons such as to help with signal acquisition, channelestimation, signal pre-coding, and so on. Some types of referencesignals may undergo the same transmitter-side processing as data (e.g.,pre-coding), while some other types of reference signals may be combinedwith other data after data has undergone at least some processing at thetransmitter.

For example, in 4 G LTE, transmission of some reference signals istransparent to the receivers. For example, the precoder/beamformer usedfor Demodulation Reference Signal (DMRS) based data transmission istransparent to a user equipment (UE) because the beamformer used fordata transmission is the same as the beamformer used for transmission ofthe reference signal and, as such, the DMRS and the UE do not know whichbeamformer is used for data transmission. Due to the transparencyproperty, explicit indication of the beamformer is not needed. Instead,implicit information related to channel properties, e.g.,Quasi-Co-Located (QCL) assumption is indicated to the UE to support datatransmission from base stations in different locations. This means thatsubsets of channel properties observed from the reference resource canbe assumed to be the same as those observed from the targeted resource,e.g., DMRS. To support multi-user multiple-input multiple output(MU-MIMO) transmissions, a UE can detect possible interference from DMRSports and perform interference suppression accordingly. No additionalindication from the base station is needed. This approach works fine forLTE because the design of LTE assumes that receiver uses digitalreceiver weights to suppress interference which means the weights can beadaptively changed after the reception of the digital baseband signal.

Different from LTE, a next generation UE, which may be operating athigher frequencies, may be expected to determine analog receive beamweights before the reception of signal because analog/hybrid beamformingmay be used at the UE. Therefore, the UE should know the interferenceinformation in advance if interference suppression/cancellation is donein the analog domain.

In some embodiments the indication of spatial QCL assumption may besupported between DL RS antenna port(s) and the DMRS antenna port(s) ofDL data channel. However, it is not known how this spatial QCLassumption is related, i.e., whether it is interference or compositechannel of multiple beams if multiple antenna ports are associated. Thetechniques presented in this document can be used to build transmittersand receivers that address these problems, and others.

Examples of Multi-Beam Indication

To support multiple beam transmission on a target resource (e.g., a DMRSport), multiple reference resources (e.g., CSI-RS resources) may beassociated with one target resource. The association can be set up viaQCL assumptions which reflect the channel properties in at least one ofthe following aspects: Doppler spread, Doppler shift, delay spread,average delay, average gain, angle of arrival, angle of departure,angular spread, or spatial correlation. Multiple sets of these QCLassumptions are associated with one targeted resource so that thechannel observed from the targeted antenna port has similar channelproperties as the composite channel of multiple CSI-RS ports/resources.When the reference and targeted antenna ports are in different duplexdirection (i.e., UL and DL), then its association refer to reciprocalchannel observed from the reference resource.

FIG. 3 shows an example configuration 300 of communication between abase station 302, which may be implemented as depicted in FIG. 2, andmay be similar to the BS 102, and a user device 304. The user device 304may be similar to the user device 106 and may be implemented as depictedin FIG. 2. As depicted in FIG. 3, the base station 302 may transmitsignals using multiple resources (e.g., CSI-RS ports) and the userdevice 304 may receive signals on a target resource, e.g., a receivingresource, e.g., a DMRS port.

If CSI-RS resource 1 and CSI-RS resource 2 are associated with one DMRSport in the aspect of angle of arrival, two angles of arrival(corresponding to the two beams transmitted from these two CSI-RSresources) are expected to be observed in the DMRS port. The signalsassociated with these two beams may have two different DMRS sequencesbut they are on the same DMRS port. In some embodiments, CSI-RS resource1 and CSI-RS resource 2 may correspond to the same layer of the dataassociated with the DMRS port.

If CSI-RS resource 1 and CSI-RS resource 2 are associated with one DMRSport in the aspect of angle of arrival, two angles of arrival(corresponding to the two beams transmitted from these two CSI-RSresources) are expected to be observed in the DMRS port. The signalsassociated with these two beams may have two different DMRS sequencesbut they are on the same DMRS port. In some embodiments, CSI-RS resource1 and CSI-RS resource 2 correspond to different layer of the dataassociated with the DMRS port.

If CSI-RS resource 1 and CSI-RS resource 2 are associated with CSI-RSresource 3 in the aspect of angle of arrival, two angles of arrival(corresponding to the two CSI-RS resources) are expected to be observedin the CSI-RS resource 3.

Each of the multiple reference resources associated with one targetedresource can be categorized as a channel part or an interference part.The UE is then indicated which resources belong to the channel part andwhich resources belong to the interference part.

For example, in the example discussed above, the UE may be indicated byBS that CSI-RS resource 1 and CSI-RS resource 2 are channel andinterference parts respectively. If CSI-RS resource 1 and CSI-RSresource 2 are associated with one DMRS port in the aspect of angle ofarrival, two angles of arrival (corresponding to the two CSI-RSresources) are expected to be observed in the DMRS port where the angleof arrival corresponding to CSI-RS resource 1 is the angle of arrival ofthe desired signal and the angle of arrival corresponding to CSI-RSresource 2 is the angle of arrival of the interference.

As another example, the UE may be indicated by the BS that CSI-RSresource 1 and CSI-RS resource 2 are channel and interference partsrespectively. If CSI-RS resource 1 and CSI-RS resource 2 are associatedwith CSI-RS resource 3 in the aspect of angle of arrival, two angles ofarrival (corresponding to the two CSI-RS resources) are expected to beobserved in the CSI-RS resource 3 where the angle of arrivalcorresponding to CSI-RS resource 1 is the angle of arrival of thedesired signal and the angle of arrival corresponding to CSI-RS resource2 is the angle of arrival of the interference.

In some embodiments, if sounding reference signal SRS resource 1 and SRSresource 2 are associated with one UL DMRS port by indication, UE usesthe same precoder/beam(s) as from these two SRS resources on the UL DMRSport to perform multi-beam/layer transmission on the DMRS port.

In some embodiments, if CSI-RS resource 1 and CSI-RS resource 2 areassociated with one UL DMRS port by indication, UE uses the same receiveprecoder/beam(s) from these two CSI-RS resources to generate thereciprocal beams on the UL DMRS port to perform multi-beam/layertransmission on the DMRS port.

In some embodiments, the BS may also indicate to the UE the power offsetfor each channel/interference component corresponding to each CSI-RSresource.

Multi-Beam Reception

To support multiple beam reception after receiving the multi-beamindication, the UE would use the information obtained from theindication to perform the subsequent reception and measurement onchannel and interference.

Upon receiving the indication, the UE knows the channel observed in theDMRS port where the angle of arrival corresponding to CSI-RS resource 1is the angle of arrival of the desired signal and the angle of arrivalcorresponding to CSI-RS resource 2 is the angle of arrival of theinterference.

If the targeted resource is DMRS, the UE steers the receive analog beamweight to the angle of arrival of the desired signal to receive thechannel part of the signal and perform channel estimation fordemodulation. At the same time, the receive beam weight is designed tonull the interference at the angle of arrival of the interference. Thenthe UE performs demodulation based on these channel and interferenceassumptions.

If the targeted resource is the CSI-RS for CSI acquisition, the UE maysteers the receive beam weight to the angle of arrival of the desiredsignal to receive the channel part of the signal and perform channelestimation for CSI-acquisition. At the same time, the receive beamweight may be designed to null the interference at the angle of arrivalof the interference. Then the UE may report CSI based on these channeland interference assumptions to the BS.

In some embodiments, the UE decides the receive beam according to poweroffset of channel interference components corresponding to CSI-RSresources.

Example Information

Some examples of the information that could be included in the report toensure a sync-up between BS and UE for the beam indication and receptionprocedure includes:

-   -   The number of components that the UE can use for signal        enhancement.    -   The number of components that the UE can use for interference        nulling.    -   The number of interfering beams that the UE can null (nulling        capability).    -   The structure of analog receive beamformer reported by the UE or        indicated to the UE. For example, a Kronecker analog beamformer        f_(RF)=f₍₁₎ ⊗f₍₂₎⊗ . . . ⊗f_((D)) where there are total D        factors and M (<D) of D factors can be used for interference        nulling and (D-M) is used for signal enhancements.    -   The codebook used for signal enhancement and the codebook used        for interference nulling.

FIG. 4 shows an example procedure 400 of multi-beam indication andreception.

At 402, the BS may perform a beam sweeping operation by sending multiplereference resources such as the CSI-RS. The beam sweeping may be usefulin an initial establishment of the beam patterns.

At 404, BS the may perform a multi-beam transmission on one targetedantenna port. BS indicates information about an association betweenmultiple reference resources and a target antenna port.

The BS may indicate the user device which of the multiple referenceresources is/are associated with channel part corresponding to the data(or to be) delivered to the user. The BS may indicate the user which ofthe multiple reference resources is/are associated with (possible orpotential) interference part corresponding to the data (or to be)delivered to another user.

At 406, the UE determines analog receive weights according to the beamindication and perform reception of an RS for CSI acquisition ordemodulation. The BS may send beam indication to the UE based on thecapability. For example, capability may include the maximum number ofreference resources associated with data and the maximum number ofreference resources associated with the interference. The UE maydetermine the analog receive weights according to the beam indicationand perform reception of RS for CSI acquisition or demodulation.

FIG. 5 shows an example procedure 500 for reporting interferencecancellation capability.

At 502, UE reports to the BS on the structure of analog beamformerimplemented at the UE including its interference nulling capability.

At 504, UE reports to the BS on the structure of analog beamformerimplemented at the UE including its interference nulling capability.

At 506, UE determines the analog receive weights according to the beamindication and perform reception of RS for CSI acquisition ordemodulation.

FIG. 6 shows a flowchart for a wireless communication method 600. Themethod 600 may be implemented at a base station. The method 600includes, at 602, receiving, by the user device, an indication about anassociation between multiple reference resources and a target resourceat the user device; wherein the association includes properties of acommunication channel to and/or from the user device, and wherein atleast one property of the communication channel is different among themultiple reference resources. The method 600 includes, at 604,performing further wireless communication using the information. Asdescribed herein, the information may be used to selectively filter outunwanted interference or filter to receive a desired signal.

In some embodiments, X (X an integer greater than 1) number of multipleresources may be indicated in the association. Each of the X referenceresources may correspond to channel part or interference part of thetarget resource supporting at least one of the following data orreference transmissions: (1) All X reference resources correspond to thechannel part of the same layer of the data or reference signaltransmission, (2) Different reference resources may correspond to thechannel part of different layer of the data or reference signaltransmission, (3) X1 (where X1<=X) out of X reference resourcescorrespond to channel part of the target resource. The remaining (X−X1)reference resources correspond to interference part of the targetresource.

In some embodiments, each reference or target resource may be one of thefollowing type of resource: (1) A reference signal resource comprisingof one or multiple ports, (2) One antenna port or antenna port group ofa reference signal resource with the same scrambling sequence, (3) Oneantenna port or antenna port group of a reference signal resource withmultiple scrambling sequences.

The method 600 may further include reporting, from the user device, areport that includes at least one of the following information of theuser device related to the information in the indication. (1) themaximum number of reference resources the user device supports, (2)Which channel properties that are assumed to be the same among thereference resources, (3) Which channel properties that can be differentamong the reference resources, (4) What types of reference resources canbe indicated.

In some embodiments, the method 600 may further include performingmeasurements on a first received signal based on the receivedinformation about the association by distinguishing a channel part ofthe first received signal from an interference part of the firstreceived signal based on the information, and recovering, using resultsof the measurements, data from a second received signal. The channelpart may correspond to user data intended for reception by the userdevice and the interference part may correspond to data beingtransmitted to another user device. In various embodiments, the channelpart and the interference part in the target resource may bedistinguished by at least one of the following ways: (1) Differentscrambling sequences in the target resource, (2) Different antenna portsin the target resource, and (3) Different groups of antenna ports in thetarget resource.

The method 600 may further include performing measurements on a firstreceived signal based on the received information about the associationby distinguishing a channel part of the first received signal from aninterference part of the first received signal based on the information,and reporting, using results of the measurements, channel stateinformation. The user device may perform data or reference signaltransmission on target resource based on the association.

In some embodiments, the association may imply that the channel overwhich a symbol on the target antenna port is conveyed can be inferredfrom the multiple channels observed over which other symbols on thereference antenna ports are conveyed. In some embodiments, the multiplereference resources associated with the same target receiving resourcehave the same channel properties with respect to a subset of channelproperties. For example, the subset of channel properties may includeDoppler spread and Doppler shift.

In some embodiments, the indication includes the power informationassociated with each of the multiple reference resources. For example,in some embodiments, the power information included the power offset(s)among the channel part(s) or interference part(s) of the target resourceassociated with the multiple reference resources.

FIG. 7 shows a flowchart for a wireless communication method 700. Themethod 700 may be implemented at a base station. The method 700 includestransmitting (704), to the user device, an indication about anassociation between multiple reference resources and a target resourceat the user device, wherein the association includes properties of acommunication channel to and/or from the user device, and wherein atleast one property of the communication channel is different among themultiple reference resources. The method 700 may also include performing(706) wireless communication using at least some of the multiplereference resources to transmit a signal to the user device. Thisoperation 706 may be a reception of a wireless message or a transmissionof a wireless signal.

In some embodiments, a wireless communication apparatus comprising amemory and a processor may be implemented such that the memory storesinstructions and the processor is configured to read the instructionsfrom the memory and implement a method or procedure described herein,e.g., the method 600 or the method 700.

It would be appreciated that the present document discloses techniquesin which Information related to multiple reference resources isindicated by BS to UE for the association with one targeted resource(i.e., one targeted antenna port) in terms of channel properties (atleast including one of the following channel properties: Doppler spread,Doppler shift, delay spread, average delay, average gain, angle ofarrival, angle of departure, angular spread, spatial correlation).

In some embodiments, the information includes the information todistinguish which reference resources are belonged to channel part andwhich reference resources are belonged to interference part.

In some embodiments, a UE performs the channel and interferencemeasurement based on the receive weights determined according to theindication. The UE may perform data demodulation based on the indicatedchannel and interference assumption. The UE may perform CSI feedbackbased on the indicated channel and interference assumption.

It will also be appreciated that using the disclosed technique, UEreports number of components that the UE can use for signal enhancementand number of components that the UE can use for interference nulling.The structure of analog receive beamformer reported by the UE orindicated to the UE. In some embodiments, a Kronecker analog beamformerfRF=f (1) ⊗f (2) ⊗ . . . ⊗f (D) where there are total D factors andM(<D) of D factors can be used for interference nulling and (D−M) isused for signal enhancements.

The disclosed and other embodiments, modules and the functionaloperations described in this document can be implemented in digitalelectronic circuitry, or in computer software, firmware, or hardware,including the structures disclosed in this document and their structuralequivalents, or in combinations of one or more of them. The disclosedand other embodiments can be implemented as one or more computer programproducts, i.e., one or more modules of computer program instructionsencoded on a computer readable medium for execution by, or to controlthe operation of, data processing apparatus. The computer readablemedium can be a machine-readable storage device, a machine-readablestorage substrate, a memory device, a composition of matter effecting amachine-readable propagated signal, or a combination of one or morethem. The term “data processing apparatus” encompasses all apparatus,devices, and machines for processing data, including by way of example aprogrammable processor, a computer, or multiple processors or computers.The apparatus can include, in addition to hardware, code that creates anexecution environment for the computer program in question, e.g., codethat constitutes processor firmware, a protocol stack, a databasemanagement system, an operating system, or a combination of one or moreof them. A propagated signal is an artificially generated signal, e.g.,a machine-generated electrical, optical, or electromagnetic signal, thatis generated to encode information for transmission to suitable receiverapparatus.

A computer program (also known as a program, software, softwareapplication, script, or code) can be written in any form of programminglanguage, including compiled or interpreted languages, and it can bedeployed in any form, including as a stand alone program or as a module,component, subroutine, or other unit suitable for use in a computingenvironment. A computer program does not necessarily correspond to afile in a file system. A program can be stored in a portion of a filethat holds other programs or data (e.g., one or more scripts stored in amarkup language document), in a single file dedicated to the program inquestion, or in multiple coordinated files (e.g., files that store oneor more modules, sub programs, or portions of code). A computer programcan be deployed to be executed on one computer or on multiple computersthat are located at one site or distributed across multiple sites andinterconnected by a communication network.

The processes and logic flows described in this document can beperformed by one or more programmable processors executing one or morecomputer programs to perform functions by operating on input data andgenerating output. The processes and logic flows can also be performedby, and apparatus can also be implemented as, special purpose logiccircuitry, e.g., an FPGA (field programmable gate array) or an ASIC(application specific integrated circuit).

Processors suitable for the execution of a computer program include, byway of example, both general and special purpose microprocessors, andany one or more processors of any kind of digital computer. Generally, aprocessor will receive instructions and data from a read only memory ora random access memory or both. The essential elements of a computer area processor for performing instructions and one or more memory devicesfor storing instructions and data. Generally, a computer will alsoinclude, or be operatively coupled to receive data from or transfer datato, or both, one or more mass storage devices for storing data, e.g.,magnetic, magneto optical disks, or optical disks. However, a computerneed not have such devices. Computer readable media suitable for storingcomputer program instructions and data include all forms of non-volatilememory, media and memory devices, including by way of examplesemiconductor memory devices, e.g., EPROM, EEPROM, and flash memorydevices; magnetic disks, e.g., internal hard disks or removable disks;magneto optical disks; and CD ROM and DVD-ROM disks. The processor andthe memory can be supplemented by, or incorporated in, special purposelogic circuitry.

While this document contains many specifics, these should not beconstrued as limitations on the scope of an invention that is claimed orof what may be claimed, but rather as descriptions of features specificto particular embodiments. Certain features that are described in thisdocument in the context of separate embodiments can also be implementedin combination in a single embodiment. Conversely, various features thatare described in the context of a single embodiment can also beimplemented in multiple embodiments separately or in any suitablesub-combination. Moreover, although features may be described above asacting in certain combinations and even initially claimed as such, oneor more features from a claimed combination can in some cases be excisedfrom the combination, and the claimed combination may be directed to asub-combination or a variation of a sub-combination. Similarly, whileoperations are depicted in the drawings in a particular order, thisshould not be understood as requiring that such operations be performedin the particular order shown or in sequential order, or that allillustrated operations be performed, to achieve desirable results.

Only a few examples and implementations are disclosed. Variations,modifications, and enhancements to the described examples andimplementations and other implementations can be made based on what isdisclosed.

What is claimed is:
 1. A method for wireless communications, comprising:receiving, by a user device, an indication about an association betweenX reference resources corresponding to multiple beams having differentangles of arrivals at the user device, where X is an integer greaterthan 1, and a target resource, wherein the association includesproperties of a communication channel to and/or from the user device andthe indication provides information each of the X reference resourcescorresponds to a channel part corresponding to data for the user deviceor an interference part corresponding to data for another user device,and wherein at least one property of the communication channel isdifferent among the multiple reference resources; and determining, bythe user device, based on a received indication, a beam weight used toreceive the channel part of a signal, wherein a determined beam weightis designed to null an interference at an angle of arrival of theinterference.
 2. The method of claim 1, wherein the X referenceresources satisfy at least one of following: (1) all of the X referenceresources correspond to a channel part of a same layer of data orreference signal transmission, (2) one or some of the X referenceresources correspond to channel parts of different layers of the data orthe reference signal transmission, or (3) X1 out of the X referenceresources, where X1 is an integer less than or equal to X, correspond toa channel part of the target resource and remaining (X-X1) referenceresources correspond to an interference part of the target resource. 3.The method of claim 1, wherein each reference resource and the targetresource is one of the following type of resources: (1) a referencesignal resource comprising one or multiple ports, (2) one antenna portor antenna port group of a reference signal resource with a samescrambling sequence, (3) one antenna port or antenna port group of areference signal resource with multiple scrambling sequences.
 4. Themethod of claim 1, further including: performing measurements on a firstreceived signal based on the received indication about the associationby distinguishing a channel part of the first received signal from aninterference part of the first received signal based on the indication;and recovering, using results of the measurements, data from a secondreceived signal, wherein channel part corresponds to data for the userdevice and the interference part corresponds to the signal for otherusers.
 5. The method of claim 1, further including: performingmeasurements on a first received signal based on the received indicationabout the association by distinguishing a channel part of the firstreceived signal from an interference part of the first received signalbased on the indication; and reporting, using results of themeasurements, channel state information (CSI).
 6. The method of claim 1,further including: performing data or reference signal transmission bythe user device on target resource based on the received indicationabout the association.
 7. The method of claim 1, wherein the associationincludes information about one or more of the following:(1) at least oneof channel properties including Doppler spread, Doppler shift, delayspread, average delay, average gain, angle of arrival, angle ofdeparture, angular spread, spatial correlation, reciprocal channelproperties, or beam correspondence, or (2) a channel observed from thetarget resource having channel properties corresponding to channelsobserved from at least some of the X reference resources.
 8. The methodof claim 1, further including: reporting, from the user device, a reportthat includes at least one of the following information of the userdevice related to the information in the indication: (1) a maximumnumber of reference resources the user can support, (2) channelproperties that are same among the X reference resources, (3) channelproperties that are different among the X reference resources, (4) typesof reference resources that can be indicated.
 9. The method of claim 8,wherein the report includes information about a first number of signalprocessing resources supported by the user device for signal enhancementor information about a second number of signal processing resourcessupported by the user device for interference nulling.
 10. The method ofclaim 1, further including: providing a feedback message for updatingthe indication about the association between multiple referenceresources and the target resource at the user device.
 11. A method ofwireless communications, comprising: transmitting, to a user device, anindication about an association between X reference resourcescorresponding to multiple beams having different angles of arrivals atthe user device, where X is an integer greater than 1, and a targetresource, wherein the association includes properties of a communicationchannel to and/or from the user device, and wherein at least oneproperty of the communication channel is different among the multiplereference resources, wherein the indication provides information each ofthe X reference resources corresponds to a channel part corresponding todata for the user device or an interference part corresponding to datafor and which reference resources among the X reference resourcescorrespond to data for another user device, and wherein the associationcorresponds to a QCL (Quasi-Co-Located) association based on a QCLassumption that each of the X reference resources and the targetresource are quasi co-located with respect to the properties.
 12. Themethod of claim 11, wherein the X reference resources satisfy at leastone of following: (1) all of the X reference resources correspond to achannel part of a same layer of data or reference signal transmission,(2) one or some of the X reference resources correspond to channel partsof different layers of the data or the reference signal transmission, or(3) X1 out of the X reference resources, where X1 is an integer lessthan or equal to X, correspond to channel part of the target resourceand remaining (X-X1) reference resources correspond to an interferencepart of the target resource.
 13. The method of claim 12, furtherincluding: distinguishing between the channel part and the interferencepart in the target resource are by at least based on: (1) differentscrambling sequences in the target resource, or (2) different antennaports in the target resource, or (3) different groups of antenna portsin the target resource.
 14. The method of claim 11, wherein theassociation includes information about one or more of the following: (1)association at least one of channel properties including Doppler spread,Doppler shift, delay spread, average delay, average gain, angle ofarrival, angle of departure, angular spread, spatial correlation,reciprocal channel properties, or beam correspondence, or (2) a channelobserved from the target resource having channel propertiescorresponding to channels observed from at least some of the X referenceresources.
 15. The method of claim 11, further including: receiving areport of a user device, wherein the indication is partly based on thereport.
 16. The method of claim 12, wherein the indication includespower information related to the channel part or the interference partof the target resource associated with each of the multiple referenceresources.
 17. A wireless communication apparatus, comprising aprocessor configured to receive an indication about an associationbetween X reference resources corresponding to multiple beams havingdifferent angles of arrivals at a user device, where X is an integergreater than 1, and a target resource, wherein the association includesproperties of a communication channel to and/or from the user device,and wherein at least one property of the communication channel isdifferent among the multiple reference resources, and wherein theindication provides information each of the X reference resourcescorresponds to a channel part corresponding to data for the user deviceor an interference part corresponding to data for and which referenceresources among the X reference resources correspond to data for anotheruser device.
 18. The wireless communication apparatus of claim 17,wherein the X reference resources satisfy at least one of following: (1)all of the X reference resources correspond to a channel part of a samelayer of data or reference signal transmission, (2) one or some of the Xreference resources correspond to channel parts of different layers ofthe data or reference signal transmission, or (3) X1 out of the Xreference resources, where X1 is an integer less than or equal to X,correspond to a channel part of the target resource and remaining (X-X1)reference resources correspond to an interference part of the targetresource.
 19. A wireless communication apparatus, comprising a processorconfigured to transmit an indication about an association between Xreference resources corresponding to multiple beams having differentangles of arrivals at a user device, where X is an integer greater than1, and a target resource, wherein the association includes properties ofa communication channel to and/or from the user device, and wherein atleast one property of the communication channel is different among themultiple reference resources, and wherein the indication providesinformation each of the X reference resources corresponds to a channelpart corresponding to data for the user device or an interference partcorresponding to data for and which reference resources among the Xreference resources correspond to data for another user device.
 20. Thewireless communication apparatus of claim 19, wherein each of the Xreference resources corresponds to a channel part or an interferencepart of the target resource supporting at least one of the followingdata or reference signal transmission characteristic: (1) all of the Xreference resources correspond to a channel part of a same layer of dataor reference signal transmission, (2) one or some of the X referenceresources correspond to channel parts of different layers of the data orthe reference signal transmission, or (3) X1 out of the X referenceresources, where X1 is an integer less than or equal to X, correspond toa channel part of the target resource and remaining (X-X1) referenceresources correspond to the interference part of an target resource.